%I
%S 1,2,5,7,13,23,25,44,110,157,751,853,964,1135,2588,2602,2807,2888,
%T 3272,4046,4798,16720,21410,22285,25888,34586,51764
%N Numbers n such that (26*10^n  107)/9 is prime.
%C For n>1, numbers n such that the digit 2 followed by n2 occurrences of the digit 8 followed by the digits 77 is prime (see Example section).
%C a(28) > 10^5.
%H Makoto Kamada, <a href="https://stdkmd.net/nrr">Factorization of nearrepdigitrelated numbers</a>.
%H Makoto Kamada, <a href="https://stdkmd.net/nrr/prime/primedifficulty.txt">Search for 28w77.</a>
%e 5 is in this sequence because (26*10^5  107)/9 = 288877 is prime.
%e Initial terms and primes associated:
%e a(1) = 1, 17;
%e a(2) = 2, 277;
%e a(3) = 5, 288877;
%e a(4) = 7, 28888877;
%e a(5) = 13, 28888888888877, etc.
%t Select[Range[0, 100000], PrimeQ[(26*10^#  107)/9] &]
%o (PARI) lista(nn) = for(n=1, nn, if(ispseudoprime((26*10^n107)/9), print1(n, ", "))); \\ _Altug Alkan_, Jul 22 2016
%Y Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.
%K nonn,more
%O 1,2
%A _Robert Price_, Jul 21 2016
